test(ingest/testing-utils): Add back delta info ignore path

[asikowitz]

For some reason, the custom operator doesn't seem to be working when running connector tests, resulting in the diffs printing AspectForDiff objects. I wasn't able to debug the custom operator, so I'm just adding the ignore path back to ignore the delta info object... It seemed to be working before, so I'd like to leave it in, e.g. if the error is due to a change by deepdiff -- it causes no harm.

I also add a custom repr method to AspectForDiff in case this happens again just to make the error messages a bit nicer, but we really shouldn't hit this.

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